Combination dental chair and engine



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1,527,475 J. P. FLETCHER ET AL COIBINATION DENIAL CHAIR AND ENGINE FiledNOV. 22, 1924 2 Sheets-Shet 1 3114mm). 0 :25 dawPflefczer fianKPSzaneFeb. 24. 1925. 1,527,475

J. P. FLETCHER ET AL COMBINATION DENTAL CHAIR AND ENGINE Filed Nov. 22,{9&4 2 Sheets-Sheet 2 itter u M Patented Feb. 24, 1925. 5

UNITED STATES PATENT OFFICE.

JOHN P. FLETCHER AND FRANK F. STONE, 0F CABLISLE, PENNSYLVANIA.

COMBINATION DENTAL CHAIR AND ENGINE.

i Application filed November 22, 1924. Serial No. 751,721.

(GRANTED UNDER AGE G33 MAEGH 3, 18 53, 22 SCSI- T. In "5.)

To all whom it may concern.

Be it known that we, JOHN P. FLn'roi-Inn and FRANK P. STONE, citizens ofthe United Eitates, and residents of Carlisle, in the county ofCumberland and State of Pennsylvania, have invented a new and usefulImprovement in a Combination Dental Chair and Engine, of which thefollowing description, in conjunction with the accom- 'panying drawings,is a specification.

This invention described herein may be used by the Government, or any ofits ofricers or employees in prosecution of work for the Government, orby any other person in the United States, without the payment to us ofany royalty thereon.

This invention relates to dental appliances more particularly it isdirected to a dental chair and engine, combined in a manner to effect aunitary structure.

One of the objects of this invention is to provide a dental engine ofthe manually operable type, susceptible of detachable engagement withthe supporting tripod of an army field dental chair and capable of beingrotatably suspended immediately beneath the head of the tripod withinthe area embraced by its spread legs, for adjustment to any positiondesired by the operator.

Another object of this invention is to effect a dental engine of thecharacter specified having a driving means in the nature of a springactuated link mechanism interposed between the fly wheel and operatingtreadle which insures a smooth, continuous and uniform powertransmission to the flexible shafting and the dental instrument withwhich it is engaged.

Other objects of this invention are, to provide a combined dental chairand engine of compact construction, which may be quickly positioned forservice and conveniently disassociated for transportation purposes andto produce an assembly of the type indicated which is simple inconstruction, of comparatively few parts and particularly adapted forthe rigorous service imposed by army field usage. I

With these and other objects in view this invention consists in certainnovel details of construction, combination and arrangement of parts tobe more particularly hereinafter set forth and claimed.

Briefly stated, this invention comprises a tripod adapted to support adental chair of the army field type, a forked standard detachably androtatably suspended beneath the head of the tripod, a fly wheel mountedin the standard, a driven pulley likewise journalled in the standard andabove the fly wheel to which it is belted, a flexible shafting coupledwith the driven pulley, a foot treadle and a link driving mechanisminterconnecting the treadle with the fly wheel, such mechanism includinga driving lever pivotally connected at one end to the standard and atits free end to the upper extremity of the link carried by the treadle,a pitman interconnecting the fly wheel crank and driving lever and ahelical spring between the pitman and the pivotal connection of thedriving lever, the spring functioning to overcome dead center and assistin rotation of the fly wheel.

Referring to the accompanying drawings in which corresponding parts areindicated by similar reference characters:

Fig. 1, is a perspective view illustrating the dental engine forming thesubject matter of this invention, operatively combined with a dentalchair of the army field type.

Fig. 2, is an end elevation of the dental engine detached from thechair.

Fig. 3, is a perspective view of the dental engine detached from thechair.

Fig. 4, is a fragmentary sectionized detail of one leg of the tripod,the angle bracket aliixed thereto and swivel connection between engineframe and bracket, and

Fig. 5, is a fragmentary sectionized detail illustrating the lower endof engine-frame, anchoring plate carried thereby and base of treadle.

As the space at the disposal of the various army units when in the fieldis more or less limited it is highly important that all material forarmy usage be constructed so as to permit of minimum spacetransportation.

Heretofore, the dental engines utilized by the army have been ofconventional type and while answering the purpose were objectionablebecause of their bulk. It is therefore among other things, the aim andpurpose of this invention to provide a combination dental chair andengine of compact construction which. may be arranged for iii shipmentin but a .part ofthe space previously required forthis purpose.

In the illustrated embodiment characterizing this invention there isshown a dental chair of the army field type comprising a body portioninvolving a standard (1) adjustably supporting a seat (2), back and headrest (at). The body portion is mounted upon a tripod comprising a head(5) to whichthe standard (1) 01" the body portion is hinged and legs(6), ('7) and (8); As-thepreceding forms no part of the presentinvention it is referred to for descriptive purposes only.

Comingnow to the invention under con sideration reference being had toFigures 2and 80f the drawings, there is shown an engine frame embodyinghead plate (9) and parallellyarranged forks (10) and (11).

' -Th'e lower-ends of forks (10) and (11) are formed with lips (12)which are provided with registering openings (13) to receive thethreaded shank (141;) of extension plate or bolt (15). This bolt when inposition andsuitably anchored with a nut. (16) securesthe lipped ends ofthe forks (10) and (11) in binding relation and atthe same time providesan anchorage tor the base (17) ot at Foot treadle (18) as clearly' shownin Fig ure 3 otthcdrawings.

Rotatably journalled between the parallel forks (10) and (11) is a flywheel (19) suitably grooved to receive belt which circumscribes the flywheel and passes over a pulley (21); This pulley (21) is keyed to a stubshaft journalled above the flywheel between forks (10) and (11).

A flexible shafting coupled as at (24) to stub shaft (22) enables rotarymovement of the flywheel to be transmitted to the flexible shaiting andthence to the dental instrument (not shown) adapted to be attached tothe free end of said shal'ting as willbe readilyunderstood withoutfurther discussion.

Toactuate fly wheel (19) foot treadle (18) is connected through a linkmechanism with crank ot the fly wheel. This link mechanism comprises alink (26) hinged at one end to the free end of treadle (18) and at itsopposite end to the outer extremity of driving lever (27); The free endof driving lever stud (28) extending laterally from the fork (11) of thestandardas clearly shown in Figures 2 and 8 of the drawings.

rt pitman (29) interconnects driving lever (27) with crank" of the flywheel one end of the pitmanbeing connected to the crank; the-free end todriving lever (27) aka peintadjacentitsouter end. With the linkmechanisnrarranged in this manner it will be evident operation of the"foot; treadle"Wiil'impart rotary movementto the fly Wheel.

(27) is p'ivotally connected to.

In order to insure proper positionment of the crank (25) for each powerthrust of pitman (29) a helical spring (30) of suitable length isconnected at one end to a pin (31) projecting from the end of stud (28).The free end of spring (30) is attached to pin (32) carried by pitman(29) and located thereon at a point adjacent its crank end. This springnot only serves to overcome dead center but by virtue of its upward pullon the crank (25) tends to assist rotation of the fly wheel and thusasures smooth and uniform power transmission from the. foot treadle tothe flexible shatting.

To enable the dental engine to be detachably connected withthe chair androtatablv suspended within the area embraced by the spread legs of itstripod, head plate (O) of the engine frame is formed with an opening(33) for the passage of an externally threaded swivel stud. upon whichare positioned washers (35) and retaining nut (36).

A bracket (37) including legs (38) and (39) is mounted on theundersurface of tripod leg (6) adjacent its upper end for co operation withstud (34:) of the engine frame as shown in Figtotthe drawing. One legofthe bracket is longitudinally slotted as at (38) for the passage ofsuitable fastening elements by which itis adjustably aflixcd to thetripodileg. The. remaining leg (39) otthe bracket underlies head of thetripod and is bifurcatedas at (40), to embrace the stud (3 1:), theturcations of the leg 39) passing between washers as clearly shown inFigure ti ofthe. drawing.

.Vhen the stud (34;) has been positioned between the 'iurcations of legas aforesaid and nut properly adjusted the engine frame while: freeto-rotate, will be securely clamped 'to the bracket? In conclusion itwill be manifest this invention provides an arrangement by which adental engine may be. readily combined with a dental chair of the armyfield type and when operatively positioned will ibe out of thewayand;disposed for convenient actuation by the operator.v

Although in the foregoing certain e.|e ments have been described as bestadapted to perform the functionsallotted-to them. nevertheless it is tobe understood that various minor changes maybe resorted to within thescope ofthe appended claims without departing from or sacrificing any ofthe principles of this invention.

Havingdescribed our invention what we claim as new and? wish .to secureby Letters Patent is:

1. Thecombination witha dental chair includinga supporting tripod; ofadental engine suspended from the tripod within the area embraced-byitsspread legs.

2. The combination with a dental chair including a supporting tripod; ofa dental engine detachably connected to the tripod and suspendedtherefrom within the area embraced by its spread legs.

3. The combination with a dental chair including a supporting tripod; ofa dental engine detachably connected to the tripod and rotatablysuspended therefrom within the area embraced by the spread legs of thetripod.

a. The combination with a dental chair including a supporting tripod; ofa dental engine in detachable engagement with one leg of the tripod andsuspended Within the area embraced by the spread legs of the tripod.

5. The combination with a dental chair including a supporting tripod; ofa dental engine in detachable engagement with one leg of the tripod androtatably suspended therefrom within the area embraced by the spreadtripod legs.

6. The combination with a dental chair including a supporting tripod; ofa dental engine, means to swivelly and detachably suspend the dentalengine from the upper end of one leg of the tripod.

7. The combination with a dental chair including a supporting tripod; ofa dental enging embodying an engine standard and means to detachablysuspend the engine standard from the upper end of one of the tripod legsand within the area embraced by said legs when spread and a dentalengine carried by said frame.

8. The combination with a dental chair including a supporting tripod; ofa bracket aflixed to one leg of the tripod, an engine standard and meansto detachably connect the upper end of the standard to the bracket toeffect suspension of the standard within the area embraced by the spreadlegs of the tripod, and a dental engine operatively associated with thestandard.

9. The combination with a dental chair including a supporting tripod; ofa bracket affixed to one leg of the tripod, an engine standard and meansto detachably and rotatably connect the upper end of the standard to thebracket to effect suspension of the standard within the area embraced bythe spread legs of the tripod, and a dental engine operativelyassociated with the standard. m

10. The combination with a dental chair including a supporting tripod;of an angle bracket adjustably connected to the upper end of one of thelegs of the tripod, an engine standard, means in connection with theupper end of the standard to detachably engage the bracket and a dentalengine operatively associated with the standard.

11. The combination with a dental chair including a supporting tripod;of a bracket affixed to the upper end of one leg of the tripod, anengine standard, means rotatably aflixed to the upper end of the enginestandard to detachably engage the bracket, and a dental engine carriedby the standard.

12. The combination with a dental chair including a supporting tripod;of a forked standard suspended at its upper end from one leg of thetripod, a fly wheel mounted in the standard, flexible shaftingoperatively connected with the fly wheel, a foot treadle carried by thestandard and a driving mechanism interposed between treadle and flywheel.

13. The combination with a dental chair including a supporting tripod;of a forked standard, coacting means on the forked standard and one legof the tripod to detachably and rotatably suspend the standard withinthe area embraced by the spread legs of the tripod, a fly wheel mountedin the standard, a flexible shafting operated by the fly wheel, atreadle carried by the standard and a driving mechanism interposedbetween the treadle and fly wheel to effect operation of the latter.

1%. The combination with a dental chair including a supporting tripod;of a forked standard, coacting means on the upper end of the standardand one leg of the tripod to detachably-and rotatably suspend the tripodwithin the area embraced by its spread legs, a fly wheel mounted in thestandard, a flexible shafting operated from the fly wheel, a foottreadle aflixed to the lower end of the standard and a driving mechanisminterposed between the fly wheel and foot treadle.

15. The combination with a dental chair including a supporting tripod;of an angle bracket secured to one leg of the tripod, a forked standard,a bolt rotatably mounted in the upper end of the standard, means on thebolt to detachably engage the bracket, a fly wheel mounted between theforks of the standard, a flexible shafting operatively connected withthe fly wheel, a foot treadle mounted on the lower end of the standardand a driving mechanism between the foot treadle and fly wheel.

16. The combination with a dental chair including a supporting tripod;of an angle bracket secured to one leg of the tripod, a forked standard,a bolt rotatably mounted in the upper end of the standard, means on thebolt to detachably engage the bracket, a fly wheel mounted between theforks of the standard, a flexible shafting operatively connected withthe fly wheel a foot treadle mounted on the lower end of the standardand a driving mechanism between the foot treadle and fly wheel, suchmechanism including meansto overcome dead center and assist in rotationof the fly wheel.

17. A dental engine comprising a standard, a fly wheel carried by thestandard, a driven shaft operatively connected with the fly wheel, afoot treadle carried by the standard and a driving mechanism interposedbetween the foot treadle and fly wheel, such mechanism including meansto overcome dead center and assist in rotation of the fly wheel.

18. A dental engine comprising a standard, a fly wheel carried by thestandard, a driven shai t operatively connected with the fly wheel, afoot treadle carried by the standard and a dr ving mechanism interposedbetween the foot treadle and fly wheel, such mechanism including a linkconstruction cooperating witha reaction spring to overcome dead centerand assist in rotation of the fly wheel.

19. A dental engine comprising a standard, a fly wheel carried by thestandard an operating crank for the fly wheel, a flexible shaftingdriven by the fly wheel a foot treadle carried by the standard and adriving mechanism interposed between the foot treadle and fly wheel,such mechanism including a driving lever pivoted at its inner end to theengine standard, a connecting link having one end hinged to the foottreadle, the other end to the outer end of the driving lever a pitmaninterconnecting driving lever and fly wheel crank and a helical springaffixed to the inner end of the driving lever and lower end of pitman,to overcome dead center and assist in rotation of the fly wheel.

JOHN P. FLETCHER. FRANK P. STONE.

